My `TLS_TRUSTCERTS=` was blank. Setting it to `/etc/ssl/certs` did not resolve the problem.
The certificate I am using is generated by Let's Encrypt. I use the combined.pem, which includes the entire chain, so the `TLS_TRUSTCERTS` shouldn't be needed in my case. The certificate is also used for webmail at https://mail.stoutner.com. You can verify that it is current and doesn't otherwise have problems by visiting the URL with a web browser. -- Soren Stoutner so...@stoutner.com 623-262-6169
